Finance Guides
Use this collection when a money question depends on time, rates, recurring payments, or cash-flow assumptions. The guides explain the formula before linking to an interactive calculator.
Loans
How Amortization Works
Learn how amortization works with a verified payment schedule, principal and interest formulas, extra-payment examples and clear charts. Explore your loan.
Read guideInterest
APR vs APY Guide
Understand APR vs APY with verified examples, compounding formulas, fee comparisons and CD yields. Learn which rate to enter and compare the numbers correctly.
Read guideInvesting
Compound Interest Examples
Follow verified compound interest examples with monthly-deposit timing, full calculation steps, present value and source references.
Read guideDebt
Debt Snowball vs Avalanche
Compare debt snowball vs avalanche with verified payments, interest costs and payoff timelines. Follow worked examples and test both methods with your debts.
Read guideHow to choose a guide
Start with compound interest for growth over time, amortization for installment loans, APR versus APY for rate comparison, and debt-payoff guides when payment order is the main decision.
Editorial method and source
Finance explanations identify inputs, timing assumptions, compounding conventions, and limitations. They are educational estimates, not personalized financial advice.
Investor.gov financial tools and calculatorsWho maintains this page
Ownership and review
Written and maintained by the Toolarithm editorial team. No review date is shown without a maintained editorial record. No independent professional review is claimed.
Methodology
The editorial team checks definitions, examples, linked tools, and cited references. Dates shown here come from the page's maintained publication record.
Read the editorial methodologyDates and sources
Review dates change only after a substantive method or content check.